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    <meta charset="UTF-8">
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    <title>求和</title>
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<script>

    console.log(average(1,2,3,4,5,6,7,8,9));
    function average(){
        var n = 0;
        for (let i = 0; i < arguments.length; i++) {
            n += arguments[i];
        }
        return n;
    }
</script>
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